1. Field of the Invention
The present invention relates to an apparatus for and a method of recording an image on a photosensitive medium by exposing the photosensitive medium to a light signal by scanning the photosensitive medium with the light signal, and more particularly to an apparatus for and a method of recording an image with a light signal on a photopolymer plate for use in printing applications.
2. Description of the Related Art
There are known optical scanning image recording apparatus for recording an area gradation image with a light signal on a photosensitive medium such as a photographic film according to a scanning exposure process. In such optical scanning image recording apparatus, the exposure power or exposure energy density of the light signal is recorded on the photosensitive medium at a certain constant magnitude regardless of the size of the image recorded on the photosensitive medium.
With the exposure output recorded at the constant magnitude, however, depending on the photosensitivity characteristics of the photosensitive medium, a desired image density may not be achieved, i.e., a highlight jump may occur, when a small image of several pixels making up a highlight halftone dot is recorded on the photosensitive medium.
Photosensitive printing plate mediums such as photopolymer plates also suffer a problem in that their desired wear resistance cannot be obtained when they record small images by exposure to light.
One solution to the above problems is to increase the exposure power of a light signal for recording the image on a photosensitive medium such as a photosensitive printing plate medium with a higher amount of exposure to light, i.e., a higher amount of recording light. The increased exposure power of the light signal is effective in increasing the wear resistance of the photosensitive medium, but tends to cause other problems of poor image quality including greater image irregularities in a large screen tint image due to an excessive amount of exposure to light, blurs on halftone dot edges, and increases in the width of thin lines.